4 wheel line lock??

Who is running it and how much does it help? I am thinking about going this route instead of transbrake. Seems to make more sense to me since your drivetrain will be preloaded instead of a sudden hit. My car is not that powerfull (430 horse plus 150hp shot). Let me know your thoughts on it. How many rpms will it hold without overpowering the line lock? Also how exactly do you guys set it up and run the lines?

We use both transbrake and line lock. For the reasons stated consistency in staging, the chassis is loaded the same each time. This is done through our delay box though. You didn't state whether or not that you are using a box.

Been there, Done that. Had 4 wheel line lock on a stock '83 cutlass.
Used it with a delay box and MSD soft touch rev limiter. Ever seen a 17 sec box car? It got a lot of funny looks when it came up on the chip, lol.
It works, but you have to make sure the brakes are pumped up good before setting it or it will push through the lights.
Mine were mounted on the inner fender right by the master cylinder. NHRA has since outlawed them on some classes.

I think the RPM's it will hold would depend on the stall of your converter.

I am not running a delay box and I have a 4000 stall coverter. Just covering my options of different ways of staging and launching the car. Of course I want the best launch and reaction time as possible. I feel that I can react faster letting go of a button versus mashing the gas.